Except for dog leashes mounted on bicycles, personal carrier-mounted dog exercising devices are unknown in the prior art. Bicycle-mounted dog leashes, on the other hand, have been around for decades. By using them, dog owners can save time: the bicyclist can gain sufficient exercise for both himself and his pet without his having to expend extended periods of time in the process, as is required of those who exercise their dogs by walking, for example.
In addition, a user reduces the hazards to which he might otherwise be exposed if he were simply pedaling a bicycle in the customary manner but with a dog's leash attached to the handlebars or to another portion of the bicycle frame or else holding the leash in one hand as he pedaled. Nevertheless, for every one of these earlier bicycle-mounted devices, only able-bodied persons are in a position to actually benefit from its use. Moreover, those who are able-bodied need to possess a remarkably high degree of athleticism. Not only must they be capable of riding a two-wheeled bicycle but also they must be able to maintain their balance and a reasonable level of control when a dog is tethered to the bicycle.
Past efforts directed toward reducing hazards for both the bicyclist and his dog have focused on providing the tethered animal with as much freedom of motion, and as great a range across which to move, as possible, while at the same time keeping the dog away from the bicycle's wheels. To meet these objectives, each prior art bicycle-mounted dog leash has included an outwardly projecting rigid structure and, attached thereto, an elongated, flexible strap which gives the tethered dog ample amounts of slack.
Unfortunately, these earlier devices whether mounted high on a bicycle frame and just behind the bicycle seat, as taught by Allred in U.S. Pat. No. 5,215,037, which issued Jun. 1, 1993, or lower down on the frame, as taught by Leon in U.S. Pat. No. 7,013,840, which issued on Mar. 21, 2006, have, because of their respective strap and the slack it provides, catered to the dog's natural tendency to pull on its leash.
Indeed, the tethered dog, and especially one that is trying its best to follow the bicyclist's lead, will pull on the flexible strap in an attempt to eliminate any slackness in it and thereby gain a better sense, through direct physical contact, of the direction in which the bicyclist wishes to head. Eliminating this slackness helps the dog because a taut strap cannot generate the slapping noises and other extraneous signals which a slack strap makes, all of which tend to confuse a tethered dog as it seeks to gain direction-giving information from the bicyclist.
Not only has the bicyclist had to compensate for the dog's natural tendency to pull on a leash, but also he has had to be ready, in an instant, to check certain erratic behavior patterns which dogs are known to exhibit. An episode of erratic behavior, such as one in which a large dog suddenly lunges sideways, could result in the tethered animal destabilizing both the bicycle and its rider, tipping them over, and injuring the bicyclist and his dog in the process.
Recognizing that a generally well-behaved dog may indulge in erratic behavior on occasion, Leon offered a bicycle-mounted dog leash designed to reduce the likelihood that a dog tethered with it could tip over a bicycle. In this prior art leash, a clamp—the only element connecting it to the bicycle frame—is attached to the bicycle's rear wheel support structure downwardly of its rear wheel axle. With the clamp so attached, the tipping moment between the point where the leash is connected to the frame and the point of contact of the bicycle's rear wheel with the ground is kept to a minimum. As a result, a sharp sidewise pull by a tethered animal tends to slide the bicycle sideways rather than tipping it over.
Turning to biomechanics, Leon was able to reduce the tipping forces further by incorporating into this same prior art leash a rigid, semi S-shaped mast. In practice, this further reduction is accomplished by adjusting the overall height of the mast during installation. Specifically, the end of the mast distal from the clamp is brought, as Leon teaches in U.S. Pat. No. 7,013,840, into a position in which this end is disposed at a height which approximates that of the dog's shoulder. With the mast's end so positioned and with the dog tethered to it by a flexible strap, the animal automatically lowers its head as it pulls sidewise, thus reducing its pulling ability.
While this prior art leash, with its mast properly adjusted, does reduce the tethered dog's pulling ability, a would-be user still needs to possess a high degree of athleticism. The bicyclist has to be able to control his bicycle whenever the dog opts to pull on the flexible strap and in whatever direction it pleases the animal to pull at any given moment.
Not surprisingly, no one in the prior art has suggested any version of a dog leash mounted on a wheelchair or the like, even though such a device could provide a handicapped person with a dog's much-needed companionship or assistance. Exactly how a mobility-impaired user can keep a wheelchair with a dog tethered to it under control at all times has remained, until now, a major stumbling block to the development of a wheelchair-mounted dog exercising device.